Selective memory dump using usertokens

ABSTRACT

Embodiments of the present invention provide efficient systems and methods for selectively dumping memory by using usertokens to specify a address range from 64-bit storage to be included or excluded from a memory dump. Embodiments of the present invention can be used to reduce the requirement for programs to manage lists of address ranges which represent pertinent data for applications.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of memory dumping,and more particularly to dumping 64-bit storage using usertoken(s) tospecify the inclusion and exclusion of certain storage into the memorydump.

When feedback is sent automatically by an operating system (OS), theinformation sent may be in the form of a ‘dump’ of information collectedfrom the computer. It is often useful to include at least a portion ofthe contents of the memory in the dump. A full memory dump in moderncomputer systems may be very large, and often not all of the informationcontained within the memory dump is useful, or needed, when analyzingthe dumped memory data for problem determination.

SUMMARY

According to one embodiment of the present invention, a method forselectively dumping memory is provided, the method comprising:validating, by one or more processors, access to a list of usertokens;determining, by one or more processors, a number of usertoken entriesfrom the list of usertokens; and specifying, by one or more processors,a range of data for each usertoken entry from the list of usertokens,wherein the range of data is associated with a section of storage.

According to another embodiment of the present invention, a computerprogram product for selectively dumping memory is provided, the computerprogram product comprising: a computer readable storage medium andprogram instructions stored on the computer readable storage medium, theprogram instructions comprising: program instructions to validate accessto a list of usertokens; program instructions to determine a number ofusertoken entries from the list of usertokens; and program instructionsto specify a range of data for each usertoken entry from the list ofusertokens, wherein the range of data is associated with a section ofstorage.

According to another embodiment of the present invention, a system forselectively dumping memory is provided, the system comprising: one ormore computer processors; one or more computer readable storage media; adumping module; at least one application configured to send at least oneusertoken to the dumping module; and a storage manager configured tomanage 64-bit storage areas using the at least one usertoken.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a functional block diagram of a computing environment, inaccordance with an embodiment of the present invention;

FIG. 2 depicts a flowchart illustrating operational steps of a dumpingmodule for accepting a list of usertokens, in accordance with anembodiment of the present invention;

FIG. 3 depicts an example of a usertoken list layout, in accordance withan embodiment of the present invention; and

FIG. 4 depicts a block diagram of internal and external components of acomputing environment, in accordance with an illustrative embodiment ofthe present invention.

DETAILED DESCRIPTION

With the introduction of 64-bit architecture in z/OS® (available fromInternational Business Machines of Armonk, N.Y.), the volume of storagehas increased beyond the limits of the 2 gigabyte (GB) address spacelimitation. Individual applications can create and access GBs of storagealone, so aggregating multiple applications can result in theutilization of vast volumes of storage. The z/OS® dumping component wasenhanced to automatically include all 64-bit storage in the dump, whenthe corresponding below storage area (i.e., below the 2 GB area) wasrequested as a dump option, regardless of the address space ownership.However, with a greater volume of data, more space is needed to save thedata, and more resources are needed to capture the data, move the data,and analyze the data. Embodiments of the present invention providemethods and systems for reducing the amount of 64-bit data capturedduring a storage memory dump through the use of usertokens, whichrepresent ranges of storage addresses.

The present invention will now be described in detail with reference tothe Figures. FIG. 1 depicts a functional block diagram illustrating acomputing environment, generally designated 100, in accordance with anembodiment of the present invention. Modifications to computingenvironment 100 may be made by those skilled in the art withoutdeparting from the scope of the invention as recited by the claims. Inan exemplary embodiment, computing environment 100 includes operatingsystem (OS) 110, application programs 130, and hardware 135. Computingenvironment 100 may include additional devices, servers, or othercomponents not shown in FIG. 1.

Hardware 135 includes one or more processors 140, memory 150, and one ormore I/O devices 160. In this exemplary embodiment, OS 110 includesdumping module 115 and storage manager 120. Dumping module 115 is adumping engine for generating memory dumps. In this exemplaryembodiment, dumping module 115 accepts a list of usertokens, obtains thematching storage address ranges from storage manager 120, and capturesthe associated data for each address range to write to the dump dataset.In this exemplary embodiment, dumping module 115 can be enhanced toaccept a list of usertoken(s) from an exploiter to dump the associated64-bit storage areas in the dump. Any type of 64-bit storage (i.e.,common, private, or shared) can be dumped using the specified usertoken.Hereinafter, all references to 64-bit storage (common, private, andshared) refer to 64-bit storage which have addresses greater than 2 GB(i.e., high storage).

Storage manager 120 contains 64-bit storage services, which support thespecification of a usertoken when creating common and/or private memoryobjects.

Application programs 130 use storage manager 120 services to obtainmemory objects. Application programs 130 identify the 64-bit storageareas that are essential for diagnostics in the event of an error andcan use a usertoken that is unique to a component or a product whenthese identified storage areas are requested via 64-bit storageservices. In this exemplary embodiment, a usertoken is unique forapplication programs 130, and application programs 130 can use oneusertoken for all of the identified 64-bit storage areas, or may usemultiple unique usertokens for the identified 64-bit storage areas.Application programs 130 can then pass a list of the usertokens todumping module 115.

FIG. 2 depicts a flowchart illustrating operational steps of dumpingmodule 115 for accepting a list of usertokens, in accordance with anembodiment of the present invention.

In step 202, dumping module 115 performs a preliminary accessibilityvalidation. In this exemplary embodiment, dumping module 115 performs anaccessibility validation to the exploiter's usertoken area, confirmingthat the supplied list of usertokens is useable.

In step 204, dumping module 115 calculates the number of usertokenentries. In this exemplary embodiment, dumping module 115 is providedwith the total length of the usertoken list, as well as one or moreusertoken entries. Dumping module 115 determines the number of usertokenentries by dividing the entire list by the known usertoken entry length.In this exemplary embodiment, one usertoken can be associated withmultiple memory objects in different types of 64-bit storage (i.e.,private or common), and at different addresses. The usertoken list isdescribed further in FIG. 3.

In step 206, dumping module 115 gathers the common storage ranges foreach common usertoken entry. In this exemplary embodiment, when thereare usertoken entries to process, dumping module 115 traverses throughthe usertoken entries to capture the matching common storage during aglobal data capture. The specified usertoken is passed to storagemanager 120, requesting the matching 64-bit common storage ranges of thememory to be included in the dump. The ranges are added to a table inanother portion of common memory, to be used to capture the associateddata later in the dump processing.

In step 208, dumping module 115 gathers the matching private storageranges for each private usertoken entry. In this exemplary embodiment,the local data capture follows a similar process as that of the globaldata capture (step 206), to capture the private storage, when theaddress space specified in the usertoken entry matches the address spacebeing dumped. The ranges are added to a table, in another portion ofstorage, to be used to capture the associated data later in the dumpprocessing.

If the address space identifier is not specified for a private storageusertoken entry, then, dumping module 115 captures the matching 64-bitprivate storage for each address space taking a part in the memory dump.This feature also becomes useful when an exploiter, for example,application programs 130, choose the same usertoken for obtaining 64-bitprivate storage in multiple address spaces. In this way, the relevantdata is captured faster, with the least amount of burden on applicationprograms 130, and the debugger has less data to look through to finduseful information. This aligns with the philosophy of First FailureData Capture (FFDC), or getting all of the required data for the firstoccurrence of a problem.

After all of the common storage and private storage ranges have beenadded to the appropriate tables, dumping module 115 captures theassociated data for each specified range, and writes the data to thedump dataset.

In some embodiments, the usertokens can be used to minimize thecapturing of sensitive data in a memory dump, for example, byassociating the sensitive data with an excluded usertoken whenrequesting a dump.

Accordingly, by performing operational steps of FIG. 2, the 64-bitstorage inclusion or exclusion from a dump is customizable by enhancingdumping module 115 to accept a list of usertoken(s) via a new parameter.The need for programs to manage lists of address ranges that representpertinent data for any application that exploits the memory usertokensis greatly reduced.

FIG. 3 depicts an example of a usertoken list layout, in accordance withan embodiment of the present invention.

In this exemplary embodiment, dumping module 115 is provided with a listof usertokens and determines the total number of usertoken entries (step204 of FIG. 2). Each specified usertoken within usertoken list 300 mustcontain enough information such that dumping module 115 is able torecognize when to capture the storage associated with the specifiedusertoken(s) during processing. For example, as depicted in FIG. 3,usertoken list 300 includes usertoken list size 302, and a number ofusertoken entries 304A-N. Each of usertoken entries 304A-N contains thestorage type (e.g., common storage or private storage), usertoken, andthe address space identifier.

FIG. 4 depicts a block diagram of computing environment 400, which isrepresentative of various components of FIG. 1, in accordance with anillustrative embodiment of the present invention. It should beappreciated that FIG. 4 provides only an illustration of oneimplementation and does not imply any limitations with regard to theenvironments in which different embodiments may be implemented. Manymodifications to the depicted environment may be made.

Computing environment 400 includes communications fabric 402, whichprovides communications between computer processor(s) 404, memory 406,persistent storage 408, communications unit 412, and input/output (I/O)interface(s) 414. Communications fabric 402 can be implemented with anyarchitecture designed for passing data and/or control informationbetween processors (such as microprocessors, communications and networkprocessors, etc.), system memory, peripheral devices, and any otherhardware components within a system. For example, communications fabric402 can be implemented with one or more buses.

Memory 406 and persistent storage 408 are computer readable storagemedia. In this embodiment, memory 406 includes random access memory(RAM) 416 and cache memory 418. In general, memory 406 can include anysuitable volatile or non-volatile computer readable storage media.

Program files are stored in persistent storage 408 for execution and/oraccess by one or more of the respective computer processors 404 via oneor more memories of memory 406. In this embodiment, persistent storage408 includes a magnetic hard disk drive. Alternatively, or in additionto a magnetic hard disk drive, persistent storage 408 can include asolid state hard drive, a semiconductor storage device, read-only memory(ROM), erasable programmable read-only memory (EPROM), flash memory, orany other computer readable storage media that is capable of storingprogram instructions or digital information.

The media used by persistent storage 408 may also be removable. Forexample, a removable hard drive may be used for persistent storage 408.Other examples include optical and magnetic disks, thumb drives, andsmart cards that are inserted into a drive for transfer onto anothercomputer readable storage medium that is also part of persistent storage408.

Communications unit 412, in these examples, provides for communicationswith other data processing systems or devices. In these examples,communications unit 412 includes one or more network interface cards.Communications unit 412 may provide communications through the use ofeither or both physical and wireless communications links. Applicationsand/or programs may be downloaded to persistent storage 408 throughcommunications unit 412.

I/O interface(s) 414 allows for input and output of data with otherdevices that may be connected to computing environment 400. For example,I/O interface 414 may provide a connection to external device(s) 420such as a keyboard, keypad, a touch screen, and/or some other suitableinput device. External device(s) 420 can also include portable computerreadable storage media such as, for example, thumb drives, portableoptical or magnetic disks, and memory cards. Software and data used topractice embodiments of the present invention can be stored on suchportable computer readable storage media and can be loaded ontopersistent storage 408 via I/O interface(s) 414. I/O interface(s) 414also connect to a display 422.

Display 422 provides a mechanism to display data to a user and may be,for example, a computer monitor or an incorporated display screen, suchas is used in tablet computers and smart phones.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the invention.The terminology used herein was chosen to best explain the principles ofthe embodiment, the practical application or technical improvement overtechnologies found in the marketplace, or to enable others of ordinaryskill in the art to understand the embodiments disclosed herein.

What is claimed is:
 1. A method for selectively dumping memory, themethod comprising: validating, by one or more processors, access to alist of usertokens; determining, by one or more processors, a number ofusertoken entries from the list of usertokens; and specifying, by one ormore processors, a range of data for each usertoken entry from the listof usertokens, wherein the range of data is associated with a section ofstorage.
 2. The method of claim 1, further comprising: capturing, by oneor more processors, the section of storage associated with the range ofdata during a data capture.
 3. The method of claim 2, furthercomprising: responsive to capturing the section of storage associatedwith the range of data during the data capture, writing, by one or moreprocessors, information associated with the section of storage to a dumpdataset.
 4. The method of claim 1, wherein the specified range of datafor each usertoken entry from the list of usertokens is passed to astorage manager.
 5. The method of claim 1, wherein the usertoken entryis associated with more than one memory object.
 6. The method of claim1, wherein each usertoken entry from the list of usertokens comprises: astorage type, an address space identifier, and a usertoken.
 7. Themethod of claim 6, wherein the storage type comprises at least one of:private storage, common storage, and shared storage.
 8. A computerprogram product for selectively dumping memory, the computer programproduct comprising: a computer readable storage medium and programinstructions stored on the computer readable storage medium, the programinstructions comprising: program instructions to validate access to alist of usertokens; program instructions to determine a number ofusertoken entries from the list of usertokens; and program instructionsto specify a range of data for each usertoken entry from the list ofusertokens, wherein the range of data is associated with a section ofstorage.
 9. The computer program product of claim 8, further comprising:program instructions to capture the section of storage associated withthe range of data during a data capture.
 10. The computer programproduct of claim 9, further comprising: program instructions to,responsive to capturing the section of storage associated with the rangeof data during the data capture, write information associated with thesection of storage to a dump dataset.
 11. The computer program productof claim 8, wherein the specified range of data for each usertoken entryfrom the list of usertokens is passed to a storage manager.
 12. Thecomputer program product of claim 8, wherein the usertoken entry isassociated with more than one memory object.
 13. The computer programproduct of claim 8, wherein each usertoken entry from the list ofusertokens comprises: a storage type, an address space identifier, and ausertoken.
 14. A system for selectively dumping memory, the systemcomprising: one or more computer processors; one or more computerreadable storage media; a dumping module; at least one applicationconfigured to send at least one usertoken to the dumping module; and astorage manager configured to manage 64-bit storage areas using the atleast one usertoken.
 15. The system of claim 14, wherein the at leastone application is configured to exploit usertokens for 64-bit storage.16. The system of claim 14, wherein the dumping module is configured to:determine a number of usertoken entries from a list of usertokens; andspecify a range of data for each usertoken entry from the list ofusertokens, wherein the range of data is associated with a section ofstorage.
 17. The system of claim 14, wherein the dumping module isconfigured to capture a section of storage associated with a range ofdata, during a data capture.
 18. The system of claim 16, wherein thestorage manager is configured to receive the specified range of data foreach usertoken entry from the list of usertokens.
 19. The system ofclaim 14, wherein the at least one usertoken is associated with morethan one memory object.
 20. The system of claim 16, wherein eachusertoken entry from the list of usertokens comprises: a storage type,an address space identifier, and a usertoken.